Conventionally, a paper feeding device for supplying sheets of paper whereon images from originals are transferred is provided in a copying machine. In such a feeding device, it is required to provide a function for supplying sheets of paper of a plurality of sizes in order to meet various sizes and copying operations such as a magnifying copying operation and a reducing copying operation.
As shown in explanatory drawings of the present invention, FIGS. 2 and 3, for the purpose of effective supply and exchange of sheets of paper, some of the conventional feeding devices of this type have a rotatable cassette 6 in each of rotatable cassette units 3 and 4 that are installed in the lower portion of a copying machine main body 1. Each of the cassette units 3 and 4 has a motor 7 in its lower portion as a power supply source for rotating the rotatable cassette 6, and thus the rotatable cassette 6 is rotated by the driving force of the motor 7. Further, sheets of paper of A-4 size are placed into the rotatable cassette 6 in the rotatable cassette unit 3, and by rotating the rotatable cassette 6, it is possible to feed the sheets of paper of A-4 size either in the longitudinal feeding direction or in the lateral feeding direction. In the above-mentioned rotatable-cassette-type feeding device, rotation of the rotatable cassette 6 is executed at a high speed in order to permit the copying machine to start its copying operation in a short time.
However, in the above-mentioned conventional rotatable-cassette-type feeding device, speed of the rotating operation is the same in both of the cases when the rotating operation is executed during a state wherein no copying operation is required and when it is executed during a copying operation. Therefore, during the state wherein no copying operation is required, when the rotatable cassette 6 is driven to rotate to a predetermined initial station, for example, by a turning-on operation of an auto-clear key, a problem is presented in that big noise is generated from the motor 7 and the driving system due to the rotating operation.